Edwards nEXT 55, Instruction Manual

Page: 58 / 116

Figure 25 RS485 multi-drop connection
1. RS485 interface on control equipment 2. nEXT pump logic interface 1. RS485 interface on control equipment 2. nEXT pump logic interface
4.7 Connection for mixed parallel and serial operation
You can use the parallel interface control inputs to control the pump. At the same time
you can use the serial interface or the USB service port (using the manufacturer's nST PC
software) to monitor different pump parameters.
Alternatively, you can use the commands sent over the serial interface to control the
pump. At the same time, you can monitor the normal signal and analogue output over
the parallel interface.
Refer to
Figure: Logic interface connection - mixed parallel and serial operation for the
schematic diagram of a system that demonstrates how to do this. The connection is a
combination of the parallel and serial connection, given in Connect the parallel control
and monitoring on page 47 and Connection for serial control and monitoring on page 49.
Options given in the sections are available in a mixed parallel and serial operation.
Note:
While serial enable is active to enable the serial link, the parallel standby and fail signals
are not available.
The multi
‑
drop connection is shown in Figure: Logic interface connection - mixed parallel
and serial operation . You can use the multi
‑
drop connection with mixed parallel and
serial operation.
You cannot use the parallel interfaces and serial interfaces at the same time to control
the pump. For example, if you start the pump by sending a start command over the
serial interface, you cannot stop the pump by using the start or stop switch on the
parallel interface. To stop the pump, send a serial stop command. Only when the serial
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